The division was raised in 1939 in Secunderabad with two brigades under command. In 1940 the 5th Division moved to Sudan and took under command the three British infantry battalions there and was reorganised into three brigades of three battalions each. The division fought in the East African Campaign in Eritrea and Ethiopia during 1940 and 1941, thence moving to Egypt, Cyprus and Iraq. In 1942 the division was heavily engaged in the Western Desert Campaign and in the fighting withdrawal to Alamein. From late 1943 to the Japanese surrender in August 1945 it fought continuously from India through the length of Burma. After the end of the war, it was the first unit into Singapore and then fought pro-Independence forces in Eastern Java.

The Division was raised at Secunderabad in India from the Deccan District Headquarters, with two brigades of three Indian infantry battalions each. It moved to the Sudan in 1940 and was joined by three British infantry battalions already there. The division was reorganised into three brigades each with one British and two Indian battalions (as was the prevailing custom).[2]

The divisional sign, of a red circle on a black background which gave the division its nickname, was selected after the first selection of a boar's head was deemed offensive to Moslem soldiers and every other animal suggested had already been selected by other newly raised divisions.[3]

Between 1940 and 1941 the 5th Division was involved in the campaign in East Africa. After periods in Egypt, Cyprus and Syria, by 1942 it was involved in the fighting in the Western Desert of North Africa and the withdrawal of the Allied troops to El Alamein. By late 1943 the 5th Division had shipped to India and took part in the campaign in Burma initially deployed to the Arakan front. After the Japanese had been defeated in the Battle of the Admin Box the division was airlifted north to take part in the Battle of Imphal and the Battle of Kohima. Thereafter, the division was almost constantly involved in the advance through central Burma until fighting ended with the Japanese surrender in August 1945. After the end of the war, it was the first unit into Singapore and then fought pro-Independence forces in Eastern Java while protecting the recovery of Allied prisoners of war who had been incarcerated there.

Lord Louis Mountbatten wrote in his memoirs paying tribute to the division whose record was "second to none", saying:[4]

“

When the Division came under my command in South-East Asia towards the end of 1943, it had already had three years' hard fighting in Africa. In 1941 it had played a leading part in the defeat of the Italian Army in the Sudan, Eritrea, and Abyssinia; in the summer of 1942 it had been very heavily engaged with the Germans and Italians in the crucial battle of the Knightsbridge 'Cauldron,' and in the fighting withdrawal across North Africa to the defence of the Alamein line...when I first met the men of this Division, soon after the formation of the South-East Asia Command—indeed it was the first Division that I visited—its reputation was already high...the Division was heavily engaged in the first land battle to be fought since the Command had been set up...and a large share of the credit must go to the Fifth Indian Division for the first decisive victory against the Japanese since they had invaded two years previously...(the) land victory at Kohima and Imphal, in which the Division played an important part, proved to be the turning-point of the Burma Campaign...The Division continued to fight and to advance throughout the rest of the war, except for one period of rest and reorganization...Its record was second to none and I was proud to have such a fine formation under my command.

The Indian 5th Infantry Division, under the command of Major-General Lewis Heath and comprising only two brigades at the time, was sent from India to the Sudan to reinforce the British forces there under Lieutenant-General Sir William Platt which had been attacked by Italian forces in Eritrea, at the time part of the Italian East African Empire. On 10 June 1940, before the arrival of the 5th Division, Platt had only three infantry battalions[5] and the machine-gun companies of the Sudan Defence Force.

The 5th Division started to arrive in the Sudan in early September 1940 and absorbed Platt's three British infantry battalions (the 1st Battalion, Worcestershire Regiment, the 1st Battalion, Essex Regiment and the 2nd Battalion, West Yorkshire Regiment,) and formed a third infantry brigade. After these rearrangements, the division consisted of the 9th, 10th and 29th Indian Infantry brigades.

For the next three months the division was involved in a series of aggressive skirmishing operations to keep the Italian forces off balance and confused as to Platt's longer-term intentions. In early 1941, Platt's forces were further augmented by 4th Indian Infantry Division, rushed from the Western Desert after the breakthrough during Operation Compass, and an attack was launched into Eritrea on 18 January. The climax of the campaign was the Battle of Keren, a fiercely fought series of engagements against superior numbers which ended with victory for Platt's forces on 1 April.

9 and 10 Brigades of 5 Indian Division were newly stationed around Tobruk when Rommels offensive against the Gazala Line commenced at the end of May 1942. Fresh to the desert, just recently equipped with obsolete anti tank guns and poor transport, they were ordered to counterattack (Operation Aberdeen) the German breakthrough. The operation was badly mismanaged by the Corps commander, tank and artillery support failed to materialise, and casualties were crippling – every one of the West Yorks officers who participated was killed or wounded. The remnants were withdrawn first to Mersa Matruh then to the rudimentary defences at Alamein, where, reformed, they garrisoned the line, formed mobile 'Jock columns' and participated in successful counterattacks in the First Battle of El Alamein in July. After the Battle of Alam Halfa in August, they were withdrawn to garrison duties in Iraq before being shipped to Burma in mid-1943.

A soldier from the 5th Division stands guard over Japanese prisoners who surrendered during the liberation of Singapore. September 1945.

At the end of 1943 the division was taking part in the Burma Campaign. It was facing the Japanese 55th Division on the coastal flank of the Arakan front. The defeat of the Japanese 55th Division, to which a large share of the credit must go to the Indian 5th Division, was the first decisive victory against the Japanese since they had invaded Burma two years previously.

From the victory in the Arakan sector the Indian 5th Infantry Division was air-lifted to the central front. 161 Brigade joined XXXIII Corps, which was beginning to arrive at Dimapur, and fought in the Battle of Kohima while the remainder of the division reinforced IV Corps, whose land victory at Kohima and Imphal, in which the Division played an important part, proved to be the turning-point of the Burma Campaign.

Except for one period of rest and reorganization, the Indian 5th Division continued to fight and to advance throughout the rest of the war, and took part in the final thrust by IV Corps down to Rangoon.

After service in Burma the Division was the first unit to be landed in Singapore as part of Operation Tiderace and was later sent to Java as part of the Allied occupation of the Dutch East Indies.[6] It saw heavy fighting during the Battle of Surabaya in November 1945.